A high percentage of college students (66-84%) have experienced a traumatic event in their lives (Bernat et al., 1998; Read et al., 2011; Vrana & Lauterbach, 1994), and 10-12% of college students meet criteria for posttraumatic stress disorder (PTSD) (Bernat et al., 1998; Read et al., 2011). A significant subset of students experience traumatic events during college: in one sample, 19% of women reported experiencing completed or attempted sexual assault since entering college (Krebs et al., 2009). College students with PTSD symptoms are more likely to drop out of college (Duncan, 2000), and while some individuals' PTSD symptoms remit over time naturally, many continue experiencing symptoms years after the traumatic event (Orcutt et al., 2000). In addition to high rates of trauma exposure, college students are at risk for problem alcohol use. Almost half (40-44%) reported binge drinking biweekly (O'Malley & Johnston, 2002; Wechsler et al., 2002), and alcohol use disorders are the most common psychiatric disorder among college students (Blanco et al., 2008). Many students drink to cope, often with PTSD symptoms (e.g., Miranda et al., 2002), and those students experience greater alcohol-related consequences than those who drink for other reasons ( Stappenbeck et al., 2013). Additionally, students with PTSD symptoms who drink are at increased risk for additional trauma exposure ( Messman-Moore et al., 2009 ). As such, drinking to cope with PTSD symptoms can lead to future risk for trauma exposure, which can then lead to more problematic drinking. Thus, for young adults with PTSD symptoms and problem drinking, college is a critical time for intervention, since effective early interventin could decrease chronicity of both PTSD symptoms and problem drinking and lessen the need for future treatment. Mindfulness treatments are cost-effective and can be delivered in a group format on college campuses where students already reside, lowering barriers to treatment access. They have already been successfully utilized for individuals with substance use disorders (Bowen et al., 2009) and PTSD (Kearney et al., 2013; King et al., 2013). However, no studies have examined mindfulness interventions for college students with both PTSD symptoms and problem drinking. The proposed project will use a randomized controlled design to evaluate a brief, group mindfulness intervention compared to referral to treatment as usual for college students with PTSD symptoms and problem alcohol use. The project will provide important information about treatment for this comorbidity as well as provide invaluable training to a promising young researcher.